Environmental Indicators: Protection of the Ozone Layer provides
information on the following indicators:
- U.S. impact on the ozone layer
- Cumulative U.S. impact on the ozone layer
- Atmospheric concentration of selected ozone-depleting chemicals
- Ozone depletion over Antarctica
- Impact of Montreal Protocol on chlorine content of the atmosphere.

References: United States Environmental Protection Agency (EPA), Office
of Policy, Planning and Evaluation, Office of Air and
Radiation. 1995. Environmental Indicators: Protection of
the Ozone Layer. Washington, DC: EPA
END_GROUP